NullReferenceException

```
Unhandled exception. System.NullReferenceException: Object reference not set to an instance of an object.
      at Ped
      at PedSyncer.Control.NavigationMesh.getInstance() in F:\Projekte\pedSyncer\src\control\NavigationMesh.cs:line 167
      at PedSyncer.PedSyncer.OnStart() in F:\Projekte\pedSyncer\src\PedSyncer.cs:line 56
```